Inductive couplers may be used in a well for purposes of wirelessly transmitting power and/or data between downhole components. The inductive couplers typically are constructed so that a coil of an inner inductive coupler is positioned within a coil of an outer inductive coupler. A time-varying current typically is communicated through the one of the coils, which causes a time-varying electromagnetic field to be generated, which induces a corresponding current in the coil of the other inductive coupler.
The efficiency of the inductive coupling is a function of how closely the coils are placed together. One of the inductive couplers may be part of an upper completion assembly, which is landed in a lower completion assembly that contains the other inductive coupler. Due to the tolerances of the well equipment, it may be challenging to position the coils of the inductive couplers so that optimum inductive coupling is achieved. One way to ensure that inductive coupling occurs is to make the coil of one of the inductive couplers significantly longer than the coil of the other inductive coupler. Thus, at least a portion of the longer coil is surrounded by or surrounds (depending on whether the longer coil is the inner or outer coil) the shorter coil. However, such an approach may be relatively inefficient, as excessive energy may be dissipated due to a significant portion of the electromagnetic field straying outside of the shorter coil.
Thus, there exists a continuing need for better ways to align inductive couplers in a well.